Bachman HO - 3 Truck Climax - Sound

[ollietom1944]

I have a HO Bachman 70 ton 3 truck Climax (DCC) and was wondering how to fit sound to it? There doesn't seem to be any space in the Loco or Tender, as both have ? Boards in them. Please help! (I'm new to this forum, and to DCC, so please spell it out for me!) Thanks gang. Regards, ollietom1944

[ollietom1944]

Thanks so much for that info, and for the suggestion I should get it installed by a professional. I agree! Next time I purchase a Loco, I'll try and get it with sound installed! Regards,
ollietom

[Tom M.]

The speaker and sound decoder both go into the rear water tank tender.  The one I have was sound ready, so it already had a speaker port in the floor.  I believe I used a round .75" speaker.  I did it a while ago, so it would be best if you measured before selecting a speaker size.  You need to remove the existing factory PC board to make room for the Tsunami 750.  Before you remove the factory board, you need to identify the power pickup wires, motor feed wires, and headlight wires.  Bachmann does a good job of having these connection points identified on the board (R+/R-, M+/M-, H+/H-, etc).  However, they do not follow the NMRA color convention for the actual wires.  To avoid problems, I solder the Bachmann wire to the appropriate Tsunami wire immediately after I remove it from the PC board.  All solder connections need to be covered with small shrink tubing.  When you wire the headlight and tender backup light, you need to drop in a 1K ohm resistor on the white and yellow wires.  If you don't, the LEDs will go "poof."

The tank tender shell is cast metal.  It is an ideal heat sink.  I mounted the flat side of the Tsunami to the inside of the tender top using Radio Shack heat sink adhesive.

It is a very tight fit.  You will need to offset the decoder to one side of the shell to clear the speaker cone.  You also have to allow room for the two resistors in the lighting circuits.

If I ever do another one, I would put the decoder in the water tank tender.   I would then mount either a small or mini oval speaker and enclosure in the fuel bunker.  I used this approach when I added sound to a non-sound ready Bachmann 80 ton 3-truck Shay.  While I had to run 2 wires from the water tank to the fuel bunker,  it wasn't such a tight squeeze trying to get it all into the water tank.

Tom

[ollietom1944]

Hi Tom,
Thanks for that info. But there is a circuit board in both the engine and the tender. What is the small one in the tender for? You state to 'remove the one in the tender, and solder each wire as you go' - are the wires on the Tsunami not the same colors, and if not how does one know what wire to solder to what? Then, once soldered, where does the original circuit board go? So many questions, sorry. Regards, ollietom

[Tom M.]

I disn't touch the board in the loco.  From the factory, the board in the water tank tender has an 8 pin NMRA plug allowing for Plug and play installation of a decoder.  However, it takes up too much room so it needs to go to make room for the Tsunami 750.

The wiring color key is included with the Tsunami instructions.  However, here is a brief explanation:

Red - right track + rail
Black - left track - rail
Orange - positive motor terminal
Gray - negative motro terminal
Blue - lighting common
White - headlight
Yellow - backup light

To hardware the decoder, you want to match the Tsunami wires to the wire formerly on the tender PC board as follows:

Red to R+
Black to R-
Orange to M+
Gray to M-
Blue to H+
White to H-
Blue to B+
Yellow to B-

Since the PC board in the tender has resistors for the headlight and backup light, you will need to also install 1 K ohm reistor between the yellow and B- and white H- connections.  If you don't the factory LEDs will go "poof."

Good luck,

Tom

[ollietom1944]

Thanks again Tom for a comprehensive answer to my probably naive question. I am totally a newbie to DCC etc. and you have answered so well that even I should be able to do this. (Hopefully) Appreciate your time and knowledge. Regards, ollietom.